Rafters of Douglas fir–larch, No. 2 grade, are to be usedat 16 in. spacing for a span of 20 ft. Solid wood blocking is providedfor nailing of the plywood deck panels. Live load without snow is20 psf and the total dead load, including the rafters, is 15 psf. Findthe minimum size for the rafters, based only on bending stress.

Per the ACI, what is the minimum girder depth (Select a uniform depth for all girders) Material properties are: - Concrete weight: wt = 150 pcf - Concrete compressive strength: f' = 4000 psi - Steel tensile strength: fy = 60 ksi - Stirrup consists of #4 bar - Framing members are not exposed to weather or in contact with soil. Answer from: 24", 30", 36", 28" 30-0¹ B4 Member Solid one- way slabs D4 83 Colm - % 30-07 Dean /16 -Sab Mark 3 co B 30/0 82 D2 TABLE 9.5(a) MINIMUM THICKNESS OF NONPRESTRESSED BEAMS OR ONE-WAY SLABS UNLESS DEFLECTIONS ARE CALCULATED U/18.5 -Ginder 15 Minimum thickness, h One end Both ends Simply supported continuous continuous Cantilever Members not supporting or attached to partitions or other construction likely to be damaged by large deflections €20 1/24 /28 /10 40-0 Beams or ribbed one- way slabs Notes: Values given shall be used directly for members with normalweight concrete and Grade 60 reinforcement. For other conditions, the values shall be modified as…

Current Attempt in Progress A composite beam is fabricated by bolting two 2.4-in.-wide by 10-in.-deep timber planks to the sides of a 0.6-in. by 10-in. steel plate. The moduli of elasticity of the timber and the steel are 1790 ksi and 28300 ksi, respectively. The simply supported beam spans a distance of 18 ft and carries two concentrated loads P, which are applied as shown. Assume LAB = LCD= 4 ft, LBc = 10 ft, b = 2.4 in., d = 10 in. and t = 0.6 in. (a) Determine the maximum bending stresses o,, o, produced in the timber planks and the steel plate if P = 3.4 kips. (b) Assume that the allowable bending stresses of the timber and the steel are 1450 psi and 25000 psi, respectively. Determine the largest acceptable magnitude for concentrated loads P. (You may neglect the weight of the beam in your calculations.) Answers: (a) o, = (b) P= LAB i i B LBC F Lodlod b Cross section C kips. d ksi, o, = LCD D ksi.

Design a rectangular one-way slab: clear dimensions (4 m x 8 m) to carry a superimposed dead load of 2 kN/m in addition to its own weight and a service live load of 4 kN/m2., The slab is fixed to beams on all edges. Use o 13 for the main & minor steel. Use fe-28 MPa and f,-420 MPa. Show neat and complete sketch (plan & cross section) of your design. Solution: Plan View showing reinforcement details Cross-section in short direction showing reinforcement details